In previously developed earplugs, a sound deadening capability of the earplug is not adjustable to varying sound deadening needs. For instance, in certain situations, a user may desire less sound deadening from an earplug, such that they may better hear certain sounds, such as sounds indicating approaching danger or conversation. In other instances, the user may desire more sound deadening from an earplug to better protect the ear or provide a more quite environment. In previously developed earplugs, the earplugs are not adjustable to meet varying sound deadening needs. Therefore, a user of previously developed earplugs was required to buy, and keep on hand, a plurality of pairs of earplugs such that the user could switch out a pair of earplugs with another pair of earplugs having a different sound deadening ability.